Transfer device for an industrial flatwork ironer

ABSTRACT

The invention concerns a transfer device between a conveyor supplying articles and a second conveyor whereon the articles are spread out, the transfer means including, between the supply conveyor and the second conveyor, a vertical passage wherein each article is successively brought in vertical position and clamps, and means for gripping the article including a slider provided with suction means. The device includes, opposite the means gripping the article, a fixed stop located on a same side of the vertical plane of the article as the supply conveyor, and against which the gripping means are urged to be supported during the phases opening of the clamps and transferring the upper end of the article onto the gripping means.

TECHNICAL FIELD OF INVENTION

The present invention provides a transfer device for an industrialflatwork ironer designated as “short edge feeding”.

Such a machine is used to stretch flat a square or rectangular articlesuch as a cloth, a draw sheet, a napkin or the like, with a view towardsubsequent processing of this article. This subsequent processing is inparticular passing the article in an ironing machine then into a foldingmachine.

The invention concerns more particularly where the cloths are introducedon the short edge without prior search for the corners of the piece.

DESCRIPTION OF RELATED ART

A known “short edge feeder” is represented in reference to FIGS. 1 to 4.This feeder includes:

-   -   From one to four feeding stations 4;    -   An unpacking table 2 and a means of transfer by stations 14;    -   A passageway 5 and the article in it;    -   A grasping and 90° transfer apparatus, 16;    -   Two movable trolleys 7, 9 along this guide beam, quipped with        clamps suit or grasping two corners to the article;    -   A guide beam 6 perpendicular to the direction of feed of the        article in this passageway;    -   A photoelectric cell 11 placed at the level of the median zone        of this passageway below it;    -   Equipment for moving the trolleys along the guide beam and    -   Equipment for controlling this movement;    -   A means or grasping the edge of the article 12 perpendicular to        the direction of feed of the article in the passageway 5,        propelled by a back and forth motion which permits grasping the        article in the front and rear position, which permits depositing        the article on    -   A conveyor 13 which permits placing the article on the        passageway 5.

The current workstations of these machines are comprised by anon-motorized band conveyor 1 supported by its own weight on a motorizedband conveyor 2. The conveyor 1 is articulated at the rear such thatsuch that the operator can retract it in order to recover the articlewhich he/she has improperly introduced.

The operator grasps the piece of linen, locates the short edge of thispiece of linen and introduces in between conveyor 1 and conveyor 2.

The piece of linen is held between the two conveyors by the exertion ofpressure by the weight of conveyor 1.

In the event that the stations are opposite one another, there exist twosolutions:

-   -   When one station transfers a piece of linen, the other is in        expectation and the operator expects to be able to introduce        his/her piece of linen.    -   To permit the operator to introduce his/her piece of linen even        if the piece of tie opposite station is still in the process of        treatment, one motorized band conveyor 3 is added per        workstation.

In the last case, the operator can introduce the product betweenconveyors 1 and 3 in the event that conveyor 2 is not free. This permitshim/her to prepare the following article.

When the cell for detecting the presence of the piece is masked by thepiece of linen introduced, the conveyor 2 starts up, the piece of linenis spread out to be transferred by the transfer means 14. The transferis made perpendicular to the direction of spread of conveyor 2 and onconveyor 15. The piece is subsequently grasped and transferred by means16 as shown in FIG. 4. This means 16 transfers the article from itshorizontal position into a vertical position in which the article is infee fall on its part situated above means of transfer 16. The transferapparatus 16 is comprised by a motorized roller 23 and two small rollers24 and 25 rotating freely placed on the motorized roller 23 and broughtinto motion by friction on this sane roller 23.

Once the article is grasped by means 16, the cross-wise movable trolleys7 and 9, equipped respectively with the clamps 8 and 10, run counter tothe article and follow it in its fall without ever disturbing themovement of the article thanks to detection apparatus 17, 18, 19 mountedon trolley 7 and apparatus 20, 21, 22 mounted on trolley 9.

The control units of trolleys 7 and 9 are comprised by:

-   -   An electronic control system linked to a unit including a        variator and a positioning card driving    -   One gear motor group per trolley each equipped we an impulse        coder;    -   One drive pulley per trolley integral with the frame of the        machine;    -   One return pulley per trolley integral with the frame of the        machine;    -   One toothed transmission belt per trolley arranged between the        drive and the return pulleys.

Trolley 7 and trolley 8 are linked to their transmission by a fixationdevice.

When the end of the article is transferred from conveyor 15 towardapparatus 16, the detection unit mounted on the trolley 7 is releasedproviding notification of the end of the piece for the edge of thearticle situated on the edge of trolley 7 in relation to the axis ofpassageway 5. In symmetry and in an interval of time prior andsubsequent to the preceding action, and when the end of the article istransferred from the conveyor 15 toward apparatus 16, the detection unit27 mounted on the trolley 9 is released, providing information on theend of the piece for the edge of the article situated on the edge oftrolley 9 in relation to the axis of passageway 5.

The detection units 26 and 27, respectively, provide information on thecompletion of the passage of the article for the left part of thearticle and the right part of the article, respectively, in relation tothe direction of advance of the article in the passageway 5. Thisinformation permits triggering closing of the clamp 8 and the clamp 10mounted on trolley 7 and trolley 9. The notice of closing associatedwith a delay adjustable by the electronic control system permitsoptimizing the grasp so that clamp 8 and the clamp 10 grasp the articleby its rear corner. Grasping the rear corners permits correcting defectsin orientation of the piece of linen in relation to the graspingapparatus 12. This correction is indispensable for guaranteeing a goodquality of processing by drying, folding and stacking which will beapplied to the piece later on.

The piece of linen grasped by the clamps 8 and 10 is subsequently heldand centered in relation to the axis of the passageway 5.

In the lower part an apparatus 29 designed to smooth the piece out canbe used to improve the quality of the deposit of the pieces. Thisapparats can be comprised by rowing brushes associated with a box wherethe piece of linen is drawn in by a system of aspiration of air.

The grasping apparatus 12 comprised by a rod extending over the entirebreadth of the machine and which is situated in a waiting position, isactivated toward the front then stopped in a position where the frontpart of the grasping apparatus 12 is tangent to the piece.

The two actions which follow consist in opening the clamps 8 and 10 andtransferring the piece by the transfer apparatus 28. This transferapparatus can, for example, be comprised by a tube closed as itsextremities including a series of small-sized orifices spaced at regularintervals over the entire length of the tube and situated on a generatorof the tube located alongside the piece to be transferred and having acompressed air feed. The transfer is brought about by injectingcompressed air for a short duration into the tube of the transferapparatus 28 and by the intermediary of an electric valve. By escapingthrough the orifices executed on the generator of the tube, the airrapidly propels the piece in a direction adjustable by the orientationof the tube.

These two actions associated with a delay adjustable by the electroniccontrol system allow optimizing the transfer. The piece falls toward thegrasping apparatus 12 which contains an air aspiration device andorifices arranged in a manner to keep the piece firmly placed over itsentire length.

The grasping apparatus 12 which is situated in the front position isactivated toward the rear. The grasping apparatus 12 places the pieceand spreads it on the conveyor 13.

The air aspiration device with which the grasping apparatus 12 isequipped is deactivated before the finish of the course of the graspingapparatus 12 to release the piece and deposit it on conveyor 13.Conveyor 13 star and carries the piece up to the following treatment.

Such a device has several inconveniences:

-   -   The falling article can be aspirated by the smoothing apparatus        which is acting upon the piece preceding the falling piece. To        avoid this dysfunction, the spacing between the pieces is        increased to the detriment of the pace of production.    -   The piece of linen can descend according to its size, state and        its weight during the transfer onto the grasping apparatus 12 at        the moment the clamps 8 and 10 open. This fall can entail a        blockage of the transfer and in this case, the piece is lost.        This drop, which takes place after having corrected the        orientation of the piece by taking the corners into the clamps 8        and 10, also entails deficiencies in orientation which        considerably reduce the quality of the following treatments:        drying, folding and stacking.    -   When the piece has been transferred on the grasping apparatus        and the transfer apparatus 12, the corners of the piece are        knocked upward or downward due to the blowing which is applied        near the corners. At this site, the blowing of the transfer        apparatus 28 has a tendency to cause the advance of the corners        in relation to the rest of the piece. This advance entails        rebounds and imprecisions in positioning the corners in relation        to the rest of the piece at the moment of contact of the piece        with the grasping apparatus 12. These imprecisions translate        into one or two corners being folded down or even folds near the        corners.

BRIEF SUMMARY OF THE INVENTION

The invention provides a device which permits increasing the pace offunction of the machine while reducing the distance between twosuccessive pieces. The invention avoids the pieces which are transferredhaving beaten down corners, and that they are thus perfectly flat.

For this reason, the device to which it relates has a conveyor forsupplying the pieces and a second conveyor on which the pieces arespread, transport devices including a vertical passageway between thesupply conveyor and the second conveyor in which each piece issuccessively brought into vertical position and grasped by its twoangles situated downstream in relation to the direction of motion by twomovable clamps on a beam oriented cross-wise in relation to theconveyors, a blowing ramp situated alongside the conveyor in relation tothe vertical plane in which the piece of fabric is located and thenozzles of which are oriented toward the conveyor, an apparatus forgrasping the piece, for example in the from of a rectangle equipped withaspiration devices situated on one side the conveyor and above it,movable longitudinally on the conveyor between an advanced position ofgrasping the piece of textile and a retracted position of depositing thepiece on the conveyor, characterized in that it contains, facing theapparats for grasping the piece, a fixed abutment situated on the sameside of the vertical plane of the pieces the supply conveyor, andagainst which the grasping apparatus is supported during the phases ofopening the clamps and transfer of the upper extremity of the piece onthe grasping apparatus.

Advantageously, the fixed abutment is covered by a band of elasticmaterial in the zone of support of the grasping apparatus. The piece offabric is thus sandwiched between the grasping apparatus and themechanical abutment which eliminates the risks of falling to the extentthat this sandwiching is firmly maintained during the transfer. The bandof elastic material permits compensating for defects in pitch and inparticular alignment between the grasping apparatus and the abutment.The piece held thus can be transferred in good condition and withoutdisturbing the corrections of defects in orientation of the piece inrelation to the grasping apparatus previously realized by the clampstaking the corners of the piece.

According to another characteristic of the invention, each prehensileclamp of an angle of the piece of textile or the support of each clampis equipped with a deflector designed to deflect the flow of air blownby the nozzles of the ramp arranged in the zones of the piece near theangles thereof to avoid these zones being subject to the flow ofcompressed air.

The deflectors thus prevent the zones near the corners of the piecebeing bent or the pieces being folded in the zones during the transferon the exit conveyor.

According to another characteristic of this device, to the extent thatit has a smoothing out system arranged below the conveyor which exertsan under-pressure, the latter is equipped with devices designed to avoida piece coming from the supply conveyor and arriving in the verticalpassage way being aspirated into the smoothing out system.

In accordance with an embodiment, this device includes a tube fed by airunder pressure situated on the same side of the passageway as the supplyconveyor and, facing the entrance of the soothing system, has orificesdistributed radially on the length of the the opening on the side of thetube where the piece should be attracted, that is an the side oppositeto the smoothing out system.

These devices permit removing the piece falling vertically from thesmoothing out system. The flow of air exiting from the tube creates anunder-pressure attracting the piece of fabric in the direction oppositeto the smoothing out device. In order to reinforce this deflectingeffect while accentuating the Venturi effect, and in order to avoiddisturbing the behavior of the pieces situated downstream in thetransfer cycle, a fixed wall forming a deflector is arranged facing theorifices arranged in the tube.

BRIEF DESCRIPTION OF THE DRAWINGS

In any case, the invention will be better understood with the aid of thedescription which follows in reference to the appended schematicdrawings representing an embodiment of this industrial flatwork ironerby way of non-limiting example.

FIG. 1 is a plan view;

FIG. 2 is an elevation;

FIG. 3 is a detailed view of a feeding station;

FIG. 4 is an elevation on enlarged scale of the transfer station betweena first supply conveyor and a second conveyor;

FIG. 5 is a front view of an extremity of the transfer device;

FIG. 6 is a perspective view of an extremity of the transfer device;

FIG. 7 is an elevation similar to FIG. 2;

FIG. 8 is a plan view of the transfer device.

DETAILED DESCRIPTION OF THE INVENTION

The device of the invention is incorporated in a flatwork ironer such asdescribed in FIGS. 1 to 4. In the description which follows, the sameelements are designated by the same reference numbers as previously.

In order to avoid bending the corner zones arranged in the upper part ofthe piece of fabric, a deflector 33 is mounted on the clamp 8 and asymmetrical deflector is mounted on clamp 10. These defectors permitsuppressing the application of blowing from tube 28 on the zones nearthe corners of the piece of fabric. These deflectors 33 and 34 aremounted on we clamps 8 and 10 or on the trolleys supporting these. Onethus avoids applying blowing in the zones of the article close to thecorners whatever the size of the piece being transferred.

The device represented in the drawing has a smoothing system 29 exertingan underpressure on the fabric when this is placed in the vertical spaceof the transfer device. The falling piece is removed from the smoothingsystem 29 by a spacing apparatus 30. This spacing apparatus is, in theembodiment represented in the drawings, comprised by a tube 30 closed atits extremities but having orifices oriented in the direction in whichthe piece should be attracted. The tube has a supply of compressed air.The scattering action of the smoothing system 29 is obtained byinjecting, for the time necessary for this removal, compressed air intothe tube 30. It is a matter of action by the Venturi effect. Theorientation and the speed of the jet of air create an underpressurewhich acts on the piece and attracts it in the direction opposite to thesmoothing system 29. The Venturi effect is reinforced by the presence ofa wall 32 serving as a deflector which orients which orients the airdownward and thereby avoids disturbing the pieces of fabric situateddownstream in the cycle of functioning of the machine.

1. Transfer device for an industrial flatwork ironer used to stretchflat square or rectangular pieces of textile for subsequent processing,between a conveyor supplying the pieces and a second conveyor on whichthe pieces are spread, the transfer device comprising: a verticalpassageway between the supply conveyor and the second conveyor in whicheach piece is successively brought into vertical position and grasped bytwo corners of said piece situated downstream; two clamps movable on abeam oriented transversally toward the conveyors; a blowing rampsituated on one side of the supply conveyor in relation to the verticalplane in which the piece of fabric is situated, nozzles of which areoriented toward the second conveyor; an apparatus for grasping the pieceoutfitted with an aspiration apparatus situated on a side of theconveyors between an advanced position of taking the piece of textileand a retracted position of depositing the piece on the second conveyor;a fixed abutment opposite the apparatus for grasping the piece, situatedon a same side of the vertical plane as the supply conveyor, againstwhich the grasping apparatus is supported during opening phases of theclamps and of transfer of an upper extremity of the piece on thegrasping device.
 2. Device according to claim 1, wherein the fixedabutment is covered by a band of elastic material in a zone of supportof the grasping apparatus.
 3. Device according to claim 1, wherein eachclamp of a corner of the piece of textile, or a support of each clamp,comprises a deflector designed to deflect a flow of air blown by thenozzle of a ramp arranged in zones of the piece near the corners thereofin order to prevent these zones from being subjected to a flow of airunder pressure.
 4. Device according to claim 1, further comprising asmoothing system arranged below the second conveyor which exerts anunder-pressure and includes an apparatus designed to prevent the piecescoming from the supply conveyor arriving in the vertical passageway frombeing aspirated into the smoothing system.
 5. Device according to claim4, further comprising a tube fed by compressed air situated on a sameside of the vertical passageway as the supply conveyor and facing anentrance of the smoothing system having orifices arranged radially overa length of the tube and opening on a side opposite to the smoothingsystem.
 6. Device according to claim 5, further comprising a fixed wallforming a deflector arranged opposite the orifices arranged in the tube.